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101.
城市化的过程离不开工业经济的发展,在新兴的城市以及在城市新兴的工业园区内,工业用地都占有极大的比重。因此,工厂企业的绿地景观与公共空间、商业空间以及其它城市空间的绿地景观一样是城市绿地景观的重要组成部分,必须引起我们的重视。作者从绿地景观设计的角度出发,结合珠海科斯特电源有限公司绿地景观设计的实例,探讨了工厂企业在绿地景观设计方面的若干问题。  相似文献   
102.
以北京某部油库区景观规划设计为例,论述了景观规划设计中空间设计与营造的方法,并通过对方案设计的依据、步骤和方法的研究,强调了空间设计是景观设计重要的组成部分,对景观总体布局起到了决定性的作用。同时,通过结合场地现有空间的分析,我们能够更加清楚地寻找到符合场地特性的设计方案,为在场地中活动的人们提供更加舒适的休闲环境,实现场地的合理利用方式。  相似文献   
103.
A Review of Fine Root Dynamics in Populus Plantations   总被引:1,自引:0,他引:1  
Production of native and hybridized varieties of Populus has received considerable interest in temperate regions as an alternative to agricultural crops and an additional wood source, while acting as a potential carbon (C) sink to offset emissions of fossil fuel-based greenhouse gases. Research of root system dynamics in Populus species is expanding, however, our understanding of the nature and role of fine roots (FR) is incomplete. The study objective, therefore, was to review the literature regarding FR production, mortality and longevity in Populus, and evaluate the magnitude and significance of the FR fraction to C sequestration. FRs, conventionally defined as less than 2 mm in diameter and responsible for water and nutrient uptake, are an essential component of the tree. Populus FRs are relatively short-lived, with reported lifespans ranging from 30 to 300 days, depending on root diameter, tree species and age, and soil environmental factors. Standing FR biomass fluctuates throughout the growing season. Fine root production generally peaks in mid-summer, and ranges between 1.0 and 5.0 mg ha−1 yr−1, while FR mortality has less seasonal amplitude. Production and mortality dynamics in Populus are highly plastic in response to soil environmental conditions, and although opposing conclusions have been proposed, research suggests soil moisture and nitrogen to be most important. Results from the literature indicate annual FR turnover to the soil C pool may be small (0.2–1.6 mg C ha−1 yr−1), but substantial in maintaining or enhancing C levels in natural and managed stands of Populus.  相似文献   
104.
简述分析了建筑物外窗的渗漏原因,并阐明了几项质量控制措施.  相似文献   
105.
建筑玻璃幕墙的节能技术分析   总被引:2,自引:0,他引:2  
随着建筑玻璃幕墙的被广泛应用,在提升建筑物的通透性、艺术性的同时,对现有的节能技术进行分析,并提出了建筑玻璃幕墙节能的技术要求及其可行性.  相似文献   
106.
LIGNUM is a whole tree model, developed for Pinus sylvestris in Finland, that combines tree metabolism with a realistic spatial distribution of morphological parts. We hypothesize that its general concepts, which include the pipe model, functional balance, yearly carbon budget, and a set of architectural growth rules, are applicable to all trees. Adaptation of the model to Pinus banksiana, a widespread species of economic importance in North America, is demonstrated.

Conversion of the model to Jack pine entailed finding new values for 16 physiological and morphological parameters, and three growth functions. Calibration of the LIGNUM Jack pine model for open grown trees up to 15 years of age was achieved by matching crown appearance and structural parameters (height, foliage biomass, aboveground biomass) with those of real trees. A sensitivity study indicated that uncertainty in the photosynthesis and respiration parameters will primarily cause changes to the net annual carbon gain, which can be corrected through calibration of the growth rate. The effect of a decrease in light level on height, biomass, total tree branch length, and productivity were simulated and compared with field data. Additional studies yielded insight into branch pruning, carbon allocation patterns, crown structure, and carbon stress. We discuss the value of the LIGNUM model as a tool for understanding tree growth and survival dynamics in natural and managed forests.  相似文献   

107.
根据工程设计经验,阐述了住宅建筑设计中排水系统的选择,排水管道的敷设要求及设备、管材选用应注意的问题.  相似文献   
108.
Turner  Jennifer  Mitchell  Stephen J. 《New Forests》2003,26(3):279-295
The effect of short day treatments (blackout) on Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) container seedlings at the time of lift and following cold storage was investigated. Variables measured included height, root collar diameter (RCD), root growth capacity (RGC), photosynthetic efficiency after –18 °C freezing (PEF), and days to terminal bud break (DBB). From one to four blackout dormancy induction treatments were started on three dates (July 12, July 26, and August 10) with 10 or 20 d between multiple blackouts. Increasing the number of blackout treatments resulted in lower RCD, lower DBB in the late winter/early spring, and higher PEF in the early fall. Later blackout start dates decreased PEF in the early fall, and increased overall height and late fall RGC as compared to earlier blackout start dates. Nurseries growing Douglas-fir seedlings from coastal Pacific Northwest provenances should be aware that blackout regimes can decrease RGC in the late fall, and cause quicker dormancy release in the early spring. Coastal Douglas-fir can be lifted and planted in the early fall, when RGC and DBB are relatively high. If planting between February and April is necessary, seedlings given blackout should be cold stored in January to maintain an adequate level of dormancy, RGC and PEF.  相似文献   
109.
This article discusses the effect of aluminum on root growth of Querucus serrata Thunb. In a 9-week hydroponics experiment, the effects of various concentrations (0 to 5.0 mM) of Al on root growth were examined. Results revealed that root biomass increases with the increase in Al concentration up to 2.5 mM, and then it tended to decrease. In the next experiment, the effects of H+ and Al3+ on roots were compared in a 4-week hydroponics experiment using three treatment solutions: control (pH 6.0), −Al (without Al, pH 3.5), and +Al (with 2.5 mM Al, pH 3.5). No clear difference in the biomass and root length between the control and −Al treated roots was observed, and root and shoot biomass were increased by Al treatment. These results confirmed that the H+ concentration level, at a pH of 3.5, is not toxic for Q. serrata and the Al-induced increase in root biomass is not caused by the amelioration of H+ toxicity by Al. In the third experiment, roots were exposed to an Al solution (pH 3.6) intermittently. This treatment clarified that Al stimulated rooting and root elongation. In the fourth experiment, the effect of 1 mM Al on root growth during a 15-month period in a sand culture were examined. This experiment confirmed that Al stimulated good growth and development of root systems at appropriate concentrations. Therefore, it is considered that Al-induced root growth enhancement occurs as a long-term and short-term phenomenon.  相似文献   
110.
唐山市玉田县中心广场景观设计,结合了玉田的历史文化,努力做到与周围环境协调统一,构思新颖、布局合理、手法独特、材料创新,达到了理想的效果。该景观设计为小城镇中心广场的绿化设计提供了借鉴。  相似文献   
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